The picture below is a quick, basic overview of your ship's statistics.
Press i to bring up your ship's inventory screen. This shows your ship's statistical info, among other things.
Click to enlarge

Your ship has nine basic statistics that are raised or lowered depending on how you equip your ship. These stats are affected by your cannons, mortars, sails, armor plating, skills, and crew members.

These nine statistics are broken up into three color groups.

1. Green for Defense: overall ship health - affected by your ship's armor plating
2. Red for Offense: damage that you cause your enemies - affected by your cannons
3. Blue for Support: speed - affected by your crew members and your sails

Let's go into a little more depth of what these are.




Defense






Offense






Support

Limdood added some very helpful information in the general forums that explain both gear levels and how you can use the stats of your cannons, crew, and gear to your advantage. I'm copying that here nearly word for word because it answers a lot of the main questions players have.

Many thanks to Limdood for posting this explanation.
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There are 8 tiers of gear:

Tier 0 is grey
1 is light green
2 is dark green
3 is blue
4 is purple
5 is pink
6 is orange
7 is yellow/gold

Gear has a "type" which basically covers what play style the gear is good for. In general, that is shown by their icon. Gear will have bonuses to some stats and penalties to others, determined by that type. So a crew designed for cannon ships will have a big damage bonus, some accuracy and some haste, and probably a hull, armor, or repair penalty. That same type of crew, at any level will always have the same stats bonuses and the same stats penalized (something like that crew will have a "big bonus" stat of damage, and a "small bonus" stat for accuracy and haste)

That particular crew, as it moved through levels, would change (whether found at different tiers or leveled up through play). Each level it would gain 10 damage, 5 accuracy and haste, and lose 10 hull....so a high level crew will benefit your damage more, but also make your hull MORE fragile - if you choose to use that type of crew.

That + or - bonus/penalty applied per level is added on top of a "base roll", which is a randomly rolled amount for each piece of gear and each stat individually.

A quest reward or boss dropped artifact (tier 7) will always have a base roll of 0.

A shop bought item, or an item found at below artifact tier will have randomly rolled base stats. I believe the range for the major stats are -20 to +20. That crew mentioned above will have a damage bonus of 70% if you got it at artifact level from a boss or quest. But if you bought it from a shop or got it at lower level and leveled it up, it could be different. An item with a +4 roll would have a 74% at artifact tier.

To check an items roll, you can hold down shift, and then mouse-over a (non-grey) item in your inventory or equipped on you. For each stat, it will show +/- [number], then another + or - (for bonus or penalty) [another number, usually the level of the item times 5 or 10].

A pink (tier 5) cannon damage crew might read 55% damage, 27% accuracy, 21% haste, -36% hull. Holding down shift would show:
Damage: +5% + 50% (+10% per level) damage
Accuracy: +2% + 25% (+5% per level) accuracy
Haste: -4% + 25% (+5% per level) haste
Hull: +14% - 50% (-10% per level) hull

Level it up again and it'll change to
65% damage
32% accuracy
26% haste
-46% hull.

That item would have rolled slightly above average on damage and accuracy, slightly below on haste, and significantly above on hull.


As for what would be a great roll for YOU, that depends on how you want to fight.

If you want to use cannons, you generally want as much damage as possible, followed by accuracy (for range), and then rounded off with luck and haste (for big critical hits and faster volleys). You often dump hull, armor, and repair, and rely on range to keep you safe and Bloodthirst (which is basically life leech) to heal you of any damage you do suffer.

If you want to use mortar, you can often COMPLETELY FOREGO using cannons at all. In which case you want Diplomacy over everything else, since it determines mortar damage and healing, and follow that up with haste for faster mortar fire, and maybe some luck. Armor and Hull can be grabbed after that, but you can safely dump damage, accuracy (you have no cannons), and repair (that's what your water barrel is for).

If you want to be a rammer, you want hull (for ramming damage and health) and mobility (you can't hurt what you can't catch up to to hit). Followed by repair, followed by armor and haste, though neither of those is super important. You'll also likely forego using cannons and often even skip using ANY mortar skills (the rammer spec mortar gives you a free use of a a slowing mortar shot, even if you can't fire any other barrel types). So you can safely dump damage, accuracy, and diplomacy. You CAN crit with ramming, but you're unlikely to find gear that boosts luck without sacrificing more important stats, so you will likely also choose to dump luck.

And now you know what stats to look for and which to avoid for the 3 main playstyles (you CAN try hybrid builds, but they're tricky to gear for and generally perform less well than the focused builds)

As obvious as this is, I somehow missed it for a while because I'm not very observant, so I thought I'd throw this out there in case you have this problem, too.

What to do with all that extra stuff you pick up that you don't want? Dropping it overboard is a hassle because sometimes your ship will just pick it right back up. When you have a smaller ship with little inventory slots, sometimes it's best to get rid of some low quality loot.


On your inventory screen, there's a little trash can icon in the bottom right corner.
Drop an item or multiple items onto that slot, then right click to destroy it.